1. Field of the Invention
This invention relates to agricultural machinery and in particular machinery pertaining to the harvesting of a grain crop and the baling of the residue from the crop.
2. Description of Related Art
In harvesting a grain crop it has been conventional practice to remove the crop utilising a harvesting machine such as a header (which may be otherwise known as a combine harvester) which processes the cut crop to separate the grain from the harvested material and to deposit the unwanted straw, chaff and other waste material (hereinafter referred to as trash) at the rear of the machine. Such trash is deposited onto the ground generally in a row behind the combine harvester and subsequently the material is collected from the ground utilising a baling apparatus which forms the trash into bales which can be either used directly as stock feed or delivered to a mill for the production of processed stock feed. A disadvantage with such practice relates to the loss of the trash between it being deposited onto the ground and collected by a baling apparatus which can result in a loss on an average of 30% of the residue. The main reason for the inefficiency relates to the inefficiency of the baler in picking up the trash from the ground.
In addition, the trash generally includes a significant quantity of weed seeds some of which can be resistant to herbicide. Therefore to deposit the trash with the weed seeds onto the ground merely serves to compound a potential weed problem, especially given the pick-up inefficiency of the baling apparatus. Therefore it has also been common practice to deliver the trash from the combine harvester into a hopper which is trailed behind or beside the combine harvester whereby the trash is subsequently deposited at a site to be burnt or otherwise destroyed. The reason for taking this later course of action is to prevent the chemical resistant weed seeds from re-entering the environment. However this action is wasteful in that it destroys a significant amount of useful material which comprises a significant proportion of the trash and it is environmentally undesirable because of the smoke created by burning of the trash and the possible danger of a loss of control of the fire.
As an alternative to the collection of the trash and depositing it at a particular site it has also been common practice to deposit the trash onto the ground and then burn the resultant windrows and remaining stubble. Not only is such a practice wasteful of a valuable resource it also is poor farming practice in that it exposes the ground to erosion during the period between the harvesting of a crop and reseeding the ground